#oocysts

Paranoia sucks! out the marrow of living life in ecstasy.  Since researching for this post, I’ve caught myself obsessively washing my hands, scouring out as much work-related grime lodged in the tiny crevices of my fingerprints.  Not just my fingers, but fruits and vegetables have been getting an abusive brushing, whose dirt-encrusted pits I’d normally shirk off.  As a farmer supposedly knowing the health of my soil, eating soil means preventative health by the pound and I proudly assert the practice.  I’d say ‘eh’ to anything I dropped on the ground or unearthed from the garden and stick my fingers and (with a little discretion) token object wherever I wanted to on and in my person, usually in my mouth.  But imagining blobs of  puss  popping up all over my eyes and in my brain like this...

Figure2. Chunky butter balls to the center- left is a toxoplasmosis parasitic cyst

or this...

Figure3. Scar tissue in the retinal region---a toxoplasmosis-infected war zone  

...and a healthy round of self-diagnosis has made me a bit paranoid of the invisible in the soil and all around us and this:

Figure 4. Cat’s regal exit.

Here we herald Cats! and Toxoplasma gondii as our starlets for the week to introduce our first parasitic symbiotic relationship case study.  A parasite is a creature that lives on or in another organism, its host, which can hurt and/or kill it.  While this may sound like a perfidious thing to do, like all other creatures, though, they’re simply “trying to hang out and reproduce” (catalyst).  However, toxoplasma’s methods of infection and consequences may remind us of freaky things in horror films and that on a psychological level, some people seem to do to each other in reality. 

T. gondii is a single-celled organism called a protozoan that lives nearly everywhere, except the Antarctic, and causes a disease called Toxoplasmosis (toxo shorthand).  As a zoonotic disease, virtually all warm-blooded animals can get infected and can pass on from an animal to humans,  but interestingly rarely causes significant problems, with exceptions.  It goes through a fairly complex life cycle wholly dependent on two types of hosts, Definitive and Intermediate hosts, which make contact with T. gondii by ingesting food or water contaminated with its eggs.  The Definitive are Cats! and it’s domesticated and wild relatives who contract it after eating small infected birds or rodents. Only the Cat Definitive can provide the cushy and nourishing stage where T. gondii can make the crowning achievement to sexually reproduce and lay eggs called oocysts along a cat’s intestinal tract.

Figure5. Toxoplasma gondii illuminated with a fluorescent dye and found along a cat’s intestinal lining.

These eggs, numbering in the millions are shed in a cat’s feces and after a week, mature to a point where they can successfully contaminate bodies of water and soil, and if ingested, are infectious.  Enter the Intermediate Host.  An intermediate host is any other warm-blooded critter like birds or rodents that accidentally eats the egg-infested poop or poop-contaminated food.  Like a definitive host, the parasite spreads throughout the intermediate’s body but never reaches sexual maturity to lay more eggs.  If a cat eats a contaminated intermediate, however, the parasite will complete its life cycle by laying a new generation of eggs to be pooped out and help repeat the cycle.  

 For humans, we open the doors for T.gondii by touching our mouth with unwashed hands after changing a kitty litter box, or even from gardening without gloves in soil freshly toxo-planted.  Eating uncooked meat, mostly of pigs or lamb, also serves as a toxo-transmission platter.   Unlike other intermediate hosts, we’re actually dead-end hosts, where although we would never or rarely be eaten by cats, we can’t transfer the parasite to a feline.  we die, we ‘ll typically never be eaten by cats to help the parasite and so all parties just die.

Figure 6.  The Center for Disease Control’s life cycle diagram of Toxoplasmosis.

To put the prevalence of this parasite in perspective, over 33% of humans around the world, approximately 3 billion people bunk up with Toxo.  In the U.S.  about 10-22% of Americans are chronically infected, while in other nations, like France, the infection rate is nearly 4 times highter due to a serious raw meat eating culture, especially that of horse flesh.   Amazingly, though,  the majority show no symptoms given a strong immune system that keeps the parasite in check.  Generally healthy cats  show similar results, which although they are toxo’s breeding center, have no sign of illness.  But it’s different with Mice and members of the rat family that for a millennia have developed an innate fear of cats with fast-acting escape measures.  In a contaminated mouse, toxo travels through its muscles, eyes and ultimately brain where it nests into cysts with tough cell walls to resists an immunity attack.  

Figure 7. A T.gondii tissue cyst in the brain

While in the brain,  the parasite turns into a puppet master and manipulates the mouse’s most crucial defense behaviors.  By crowding out the amygdala region of its brain with cysts, it shuts down the mouse’s sense of fear and anxiety.  It also desensitizes it to cat pee, which normally would fire red flags for it to escape.  The disease also weirdly affects a mouse’s dopamine levels, a neurotransmitter that spreads sensations of calm and even euphoria.  As a result, a duped mouse surrenders to the formidable jaws of its enemy.  Through this mind game, T.gondii completes it cycle of life and evolutionary goal.

This raises profound implications for the 3 billion humans with toxo, and questions whether we really have complete agency over our decisions and personalities, or are we at the behest of dictators, both macro or microorganismal.  In the words of Lennon, ‘quit playing these mind games’:

Film 1 . Mind Games -John Lennon

Only very limited and incomplete research has explored this question.   From the scant studies done, toxoplasmosis in humans seems to affect our behaviors but strangely affects the genders differently.  One study in the Czech Republic found a group of military men who were infected with a latent or dormant form of the disease 6 times more likely to get in car accidents than the uninfected.   Other tests indicated that men tended to be more curmudgeonly,messy, and oddly enjoy the smell of cat urinte.   Contrarily, women, were found to be more social, behave like “sex-kittens”, and yet find cat urine repulsive.  

These results don't seem as existentially pressing or suicide-driving, but for those people who are infected and do demonstrate symptoms of the disease, the consequences are severe, but not mind-control.  Some of the risks include extreme brain and eye inflammation that can cause neurological damage and blindness.  AIDS patients and the elderly suffer the highest risks since they already have a  crumbled  immune system.  Pregnant women are also at risk, and although they may show no symptoms, they may suffer miscarriages, or pass on the disease to their babies who later in life may experiences some of the aforementioned problems.  

Despite these harrowing afflictions, if the disease is caught early, there is treatment and anti-retroviral drugs for AIDS patients to suppress it.  

Toxo-prevention as a Social Justice Issue:

To some researchers, toxoplasmosis is thought to be an ‘equal-opportunity’ parasite’,  affecting anyone regardless of race, income status and even location.  Still,  it is more common in places with hot, humid climates and lower altitudes.  However, In the U.S. toxo  is more common in southern states among  lower income Black Americans.  The Center for Disease Control labels these parasites one of the five Neglected Parasitic Infections, since they disproportionately affect impoverished communities with lower access to medical facilities, education, and political status.

Sharing information, educating and empowering others with healthy habits and resources, and making connections with our communities at risk are key to protecting our loved ones.  And, you needn’t worry about your cats.  In fact, folks with cats have no higher risk than cat-less people for a number of reasons, including and most importantly that many pet cats never get infected. 

Clean out their litter boxes often, please, and wear gloves if you’re pregnant or have someone else do the tossing. More common sources are infected meats, so be sure to fully cook the flesh of whatever, and, please, wash your hands.   

To quell my paranoia, mucking around in the garden will not represent a toxo-death pit waiting for me to surrender my defenses, unless, I swim naked all wide-mouthed in a mountain of week-old cat poop, but it’s hard to tell if and when T. gondii will show me the way.  

Figure 8. Dear David Bowie, thanks for all the words of wisdom, searing sounds and vision, and, oh  to be humble, ecstatic, and creatively compassionate animals.

BIOTA Staff Spotlight:

This week, meet Basim Usmani, the maestro behind the soundtrack of BIOTA’s documentary episodes.  While crafting excellent sonic partners for you on your  BIOTA forays, he took a bit of time to share his insight into the values of learning from relationships, and especially from octopoidal mothers.

-What rivets you about symbiosis?

Symbiosis is  about fulfilling potential; it’s the best remedy to existential angst. It's also the process of two separate halves becoming whole again. The natural order is not finite but infinite, and abut possibilities and combinations. There is nothing that isn't a mutation, and nothing ever stops growing. 

-What relationships resonate the most with you?     In a very loose sense and although not a symbiosis, the way certain lifeforms produce and raise offspring is my favorite type of relationship structure. I have a soft spot, especially for Octopi. When they lay their eggs, they give up eating and sleeping all together. The mother's watchful eye never wanders. She spends her limited energies cleaning and aerating her eggs, and keeping them undetected by predators. Then they hatch, and she passes away shortly after.  [Read more about the fascinating story of the hardest working octopoidal moms in the world, here and here.]

-What compels you to contribute to this group?

I've been playing mostly live music since I was a teenager and have never really composed something. For me this is a new type of symbiosis; I know how to be a part of a live band that is made up of parts but sounds like a unit. Now, instead of being one part of a band I am one part of the BIOTA experience. It's a great challenge and new way of growing.

References: [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13]